This is a small “topper” I made to sit on top of the NES Slots display.  It can hold manuals, or even another game if needed.  The angle is much shallower to allow for a wider storage area.  Feet on the bottom will slot into the indentions on top of the NES Slots nicely. 

Print on it's back and no supports needed.  BambuLab P1S, 10% infill, default speeds: 2h34m.